Tracing nitrate sources with dual isotopes and long term monitoring of nitrogen species in the Yellow River, China.

ABSTRACT: A heavy load of nitrogenous compounds reflects nutrient loss and influences water quality in large rivers. Nitrogenous concentrations and dual isotopes of nitrate were measured to ascertain the spatial and temporal distributions of nitrate transformation in the Yellow River, the second-longest river in China. Assessment of the long-term record indicates that [NO₃^--N] has increased by two-fold over the past three decades. Weekly observation of ammonium over a twelve-year period revealed high concentrations and suggests impairment of water quality, particularly since 2011. The estimated total dissolved nitrogen flux was 7.2 times higher in middle reaches than that at head waters. Anthropogenic nitrogen sources become more important in lower section of the upper reaches

SUBMITTER: Yue FJ 

PROVIDER: S-EPMC5561216 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature